The use of cardboard boxes for fruits and other perishable products is currently notably widespread, and the number of boxes that are manufactured is therefore high.
As is also known, cardboard boxes are obtained from a sheet duly stamped out, with cutting and folding lines in order to be able to carry out the strengthening and the appropriate shaping of the box, a process that is performed by means of machines or molds into which the stamped out cardboard sheets are introduced one at a time in order to carry out the appropriate folding of its ends and flaps and obtain the corresponding box in each case.
Owing to the existence of various types of box, the machines or molds will have the appropriate elements for shaping the specific type of box that is intended.
In this regard, the fact can be highlighted that there exists a very characteristic type of box that includes a base, some larger sides, some front ends, some flaps for one and another wall for folding on contiguous ones, thus strengthening the box, and an upper horizontal bridge in correspondence with each side, in such a way that the two bridges determine a resistant means of support for permitting stable stacking of boxes.
The molds used in shaping this type of box include certain side guides in which the shaping components are mounted, provided with movement or displacement both longitudinal and transverse for being adapted to the dimensions of the box it is intended to shape, in such a way that the extended cardboard sheet is arranged among those shaping elements, these being adjusted to the dimensions of the contour which the box has to have, in order to then effect a downwards push of the sheet, which is done by means of a core resting on the sector that is going to form the bottom, this core descending and folding the sides and front ends, as well as the corresponding extensions and flaps.
In other words, the descent of the cardboard sheet entails pushing into the vertical position of the sectors forming the front ends and sides, while the flaps and/or extensions attaching on to the sides and/or the front ends, as well those which are going to form the upper horizontal bridges, are duly folded from the final positions so that the box becomes perfectly strengthened.
There are molds for shaping boxes in which the bridges are carried out on the front ends. However, when it is wished to form boxes with bridges in the larger sides it is necessary to effect a series of modifications or exchanges of elements or pieces of the mold so that, in most cases, it is more profitable for the manufacturer to have a second type of mold.
Nevertheless, molds are costly and imply a very considerable economic sum, because of which it would be useful to have a mold permitting both types of box to be shaped, in other words, those in which the upper horizontal bridges are located in correspondence with the sides or those where they are in correspondence with the front ends.